614
FXUS61 KLWX 161649
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
Issued by National Weather Service State College PA
1249 PM EDT Wed Sep 16 2026

.WHAT HAS CHANGED...
The forecast remains on track, so no major adjustments were
necessary. The primary period of uncertainty continues to be
Sunday into early next week, as a frontal system meanders
nearby. This is reflected in a highly uncertain temperature
forecast.

&&

.KEY MESSAGES...
- 1) Turning warmer and more humid with a return of shower and
  thunderstorm chances for Thursday and Friday.

- 2) Rain-free and less muggy conditions are likely on Saturday,
  before the weather turns more unsettled again from Sunday into
  next week.

&&

.DISCUSSION...
KEY MESSAGE 1...Turning warmer and more humid with a return of shower and
thunderstorm chances for Thursday and Friday.

A ridge of high pressure, both at the surface and aloft, is
continuing to provide sunny skies this afternoon, with
temperatures heading well into the 80s for most areas. This
will lead into a mostly clear start to the night, but cloudiness
is expected to increase after midnight from the north and west
(first encroaching on the Alleghenies).

For Thursday, the prospects for showers and thunderstorms will
increase by mid to late afternoon, especially for the
Alleghenies, the Shenandoah Valley, and the metroplex. This is
tied to a slow moving cold front, making a gradual approach from
the Ohio Valley and Pennsylvania. As you head farther southeast
through Virginia and into the coastal plain, the chances for
rain should decrease. Thursday looks like the warmest day of the
week, although this is contingent on how much sunshine/heating
can take place earlier in the day. At this juncture, we`re
expecting highs well into the 80s again, with parts of the
Shenandoah Valley up towards the metroplex perhaps making a run
at 90.

By Friday, the frontal boundary itself should be across central
to southern VA. This will lead to a continued chance of showers,
along with somewhat cooler readings as compared to Thursday.

KEY MESSAGE 2...Rain-free and less muggy conditions are likely on Saturday,
before the weather turns more unsettled again from Sunday into
next week.

Current indications point to a rain-free start to the weekend,
with the above mentioned cold front pushing down into the
Carolinas, and weak high pressure building down from the north.

However, signals also point to more unsettled weather from
Sunday into next week, as a persistent upper ridge axis gets
shunted towards the deep South, allowing upper-level impulses
to move across the Mid-Atlantic from the west. This should
provide the impetus for at least hit and miss showers and
thunderstorms on a daily basis.

&&

.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
15z TAF update for DCA, IAD and BWI features only very minor
changes. Predominantly VFR conds are expected areawide through
18z Thurs. Expect a light southerly wind of 5-10 kts this
afternoon and generally light and variable winds tonight. A
light southerly breeze will develop again on Thursday.

Previous discussion below....

While Canadian high pressure has slowly moved toward the
Atlantic coast, its influence will help maintain VFR conditions
into Thursday morning. Gradients remain weak with light
southerly winds expected. Ahead of an approaching cold front,
showers and thunderstorms return to the forecast on Thursday.
The western TAF sites would see the most likely impacts, with
convection likely to weaken further to the east. Outside of any
storm development, VFR conditions continue on Thursday with
southerly winds around 5 to 10 knots. A cold front moves through
the region early Friday which yields a shift to northerly
winds. Afternoon gusts could approach 15 to 20 knots, with any
storm chances back toward central Virginia.

High pressure passing to our north shifts winds out of the east to
southeast Saturday, turning southwesterly by Sunday. Over the
weekend, gusts up to 15 to perhaps 20 knots are possible. In
general, expect predominantly VFR conditions to persist, but
flight conditions could deteriorate as shower and thunderstorm
potential increase late in the weekend.

&&

.MARINE...
Earlier elevated southerly winds have weakened with maximum
gusts currently around 10 to 15 knots. Canadian high pressure
remains nearby into tonight which will favor tranquil weather
over the waterways.

By Thursday, this ridge edges offshore ahead of the next cold
front. Ahead of this system, southerly winds increase which
could near Small Craft Advisory levels on Thursday
afternoon/evening. This is particularly the case over wider
waters of the Chesapeake Bay due to southerly channeling. The
cold front crosses the waters early Friday which shifts winds
over to northerly. Breezy conditions in the wake could again
near advisory levels. As high pressure tracks across southern
Quebec, marine winds turn northeasterly into Friday night with
gusts around 10 to 15 knots.

High pressure passing to our north shifts winds out of the east to
southeast Saturday, turning southwesterly on Sunday. Over the
weekend, gusts up to 15 to perhaps 20 knots are possible.

&&

.TIDES/COASTAL FLOODING...
As winds have turned more south to southeasterly, the onshore
flow has raised tidal anomalies to just below 1 foot. This has
been enough to push a few of the more sensitive locations into
the Action stage. Until the cold front moves through early
Friday, water levels will remain somewhat elevated. Although no
tidal site is shown to experience any coastal flooding, it will
need to be monitored. This is particularly the case at
Annapolis, especially during the higher of the two astronomical
high tides.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...None.
VA...None.
WV...None.
MARINE...None.

&&

$$

DISCUSSION...99
AVIATION...BRO/KVH/99
MARINE...BRO/KVH